This study aimed to evaluate the effect of types of horticultural activities among elderly individuals in a senior citizen learning camp. We arranged four horticultural activities: Grass Doll, Kokedama, Rocky Leaf Prints, and Herb Tasting and Smelling. Twenty-seven senior citizens (60 to 76 years) were recruited to participate. We assessed their physiological and mental state before and after the activities by measuring heart rate variability (HRV), pulse rate, blood pressure, salivary amylase activity (SAA), and Profile of Mood States (POMS). Results showed that SAA was significantly lower after the Rocky Leaf Prints, Herb Tasting and Smelling, and Kokedama. Pulse rate had a downward trend after the four horticultural activities. The ratio of low frequency (LF) over high frequency (HF) results showed that the Rocky Leaf Prints had a larger downward trend, followed by Herb Tasting and Smelling. POMS scores indicated significant improvement for Rocky Leaf Prints and Herb Tasting and Smelling. The types including artistic creation and food tasting were promising methods for psychological relaxation, stress reduction, and vigor enhancement for elderly persons. Findings showed that the impact of activities involving contact with plants was more significant in short-term activities. We hope this study can help plan the horticultural activities of the elderly in the future.

In order to improve the bioremediation efficiency of petroleum-contaminated soil, five test groups were selected in this study, including native bacteria, Acinetobacter venetianus, Vetiveria zizanioides L., and Vetiveria zizanioides L. combined with Acinetobacter venetianus and biochar to compare the degradation efficiency of petroleum-contaminated soil. The results of the study showed that after a six-month bioremediation, there was no significant difference between the native bacteria and the A.V. bacteria group in the removal efficiency of TPH, and the proportion of degradable TPH accounts for about 50~70%. The removal efficiency of TPH could be increased by 18.1–29% by increasing the phytoremediation of Vetiveria zizanioides L. The cultivation of Vetiveria zizanioides L. could not only stabilize the soil’s pH and conductivity but could also increase the soil’s bacterial abundance. It was suggested that bioremediation could be carried out through the combination of native bacteria and the planting of Vetiveria zizanioides L. Although the addition of biochar to the soil was able to improve the remediation effect of Vetiveria zizanioides L., it would increase the soil conductivity and reduce the abundance of soil bacteria. Therefore, it was recommended to reduce the conductivity of biochar before adding it, which may improve processing efficiency.

Heritage trees carry both botanical and historical value for a city’s resilience and sustainability and hence are precious and unique. Their transplant is costly and very rare due to tremendous cost and 100% survival requirement by law. Rootless transplant is even more detrimental to the heritage tree due to removal of roots infected by brown root rot (BRR) before transplanting. This study examined the adventitious roots (AR) induction ability of the Ficus elastica Roxb. heritage tree infected with BRR. The experimental design considered three factors: root diameter (RD), wounding method (WM), and auxin solution on aerial roots under fractional factorial experiment in completely randomized design (CRD). There were four RD groups: RDI (RD < 2 cm), RDII (2 ≤ RD ≤ 4.3 cm), RDIII (4.3 < RD ≤ 22), and RDIV (RD > 22); three WMs: cutting off (CF), girdling (GD), and rectangular shape peeling (RP) of aerial roots; and three auxin solutions: 2000 mg·L⁻¹ IBA(Indole-3-butyric acid) (2B), 2000 mg·L⁻¹ IBA + 2000 mg·L⁻¹ NAA(1-Naphthaleneacetic acid) (2NB), and 4000 mg·L⁻¹ IBA (4B) plus water as control (C). The number of rooting wounds, number of roots, and the mean length of the three longest adventitious roots in each wound were recorded to evaluate the AR rooting performance. Twenty four treatment combinations including 328 wounds were tested. The results showed that rooting ability was significantly correlated with RD and WM. Smaller RDs had better rooting and declined with increased RDs. CF had the best rooting followed by GD and then RP. Auxin solution did not significantly affect the rooting ability. It may be due to the abundant endogenous auxin in the heritage tree, which mitigated the effect of exogenous auxin for AR induction. We conclude that cutting off small-diameter aerial roots is the best approach to induce ARs from rootless F. elastica heritage trees to enhance transplantation success.

Weathered petroleum-contaminated soil was treated with Vetiveria zizanioides (Vetiver) and Cymbopogon nardus (Lemongrasss) to investigate the efficiency of phytoremediation. The initial total petroleum hydrocarbon (TPH) concentration of soil was 3000−8000 mg/kg, and after 6 months, the TPH concentrations were degraded by 50−75% under the action of soil native microbial. Planting vetiver and lemongrass stabilized soil pH and electrical conductivity, and it accelerated the decomposition of TPH in soil. Planting vetiver showed a better effect. After 6 months of planting, the TPH decomposition efficiency reached about 90%, and most of the easily decomposed TPH has been decomposed. The results of rhizosphere soil microbiota analysis also showed that planting vetiver increased the abundance of soil microbiota.